Give your leg a lick if you want to know how healthy your heart is. How salty is it?

A study in the Journal of the American Society of Nephrology says your skin’s sodium content is linked to the enlargement and thickening of a certain place in your heart — its left ventricle. The researchers based the results on data from 99 patients with chronic kidney disease, an ailment which puts people at higher risk of heart problems and death. Sodium intake is usually measured by levels in the urine, but they were instead relying on the idea that our muscles and other tissue store sodium, and measured skin in the subjects’ calves as well as the mass of their left ventricles. The findings suggest that in those patients with increased skin sodium levels, “interventions that reduce skin sodium content might improve cardiovascular outcomes.”

Read: Your Tongue Loves Salt

The condition of the heart’s left ventricle is critical because it is the “main pumping chamber,” the Mayo Clinic explains. When its walls enlarge and thicken, a condition known as left ventricular hypertrophy, “the enlarged heart muscle loses elasticity and eventually may fail to pump with as much force as needed.” It is more likely to occur in people with high blood pressure and puts a person at higher risk for a heart attack.

A high sodium intake has been linked to high blood pressure and heart disease and, indeed, the American Society of Nephrology said in a statement about the findings that some experts believe ingesting too much sodium might influence whether people with chronic kidney disease develop these heart problems.

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The amount of salt in your skin says a lot about your heart’s health. Pixabay, public domain

“Our finding of a strong relationship between skin sodium and changes in the structure of the heart suggests that interventions that reduce skin sodium content — for example, dietary sodium restriction or medications that lead to increased sodium excretion — may have beneficial effects on the heart in patients with kidney disease,” Dr. Markus Schneider, from Germany’s University of Erlangen-Nuremberg, said in the statement.

The study results also found a correlation between the skin’s salt content and blood pressure.

People with kidney disease may not necessarily be eating more salt than normally recommended just because their sodium levels are high. The U.S. National Institute of Diabetes and Digestive and Kidney Diseases explains that our kidneys are supposed to filter it out of our bodies, but when they are damaged they do not perform that job as well as healthy kidneys. “This can cause sodium to stay in your body and make your blood pressure go up.”

The federal institute recommends eating more fresh foods, cooking using other spices in place of sodium and regularly checking nutrition facts at the supermarket to help lower sodium intake.

Source: Eckardt K, Schneider MP, Raff U, et al. Skin Sodium Concentration Correlates with Left Ventricular Hypertrophy in CKD. Journal of the American Society of Nephrology. 2017.

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